The invention relates to a filament organizer to prevent filament damage during transit and more particularly to an organizer of at least one filament in the form of an optical fiber to position the optical fiber during processing of an end thereof.
Glass has been used for centuries as a material for controlling and modifying the properties of light beams. A recent and rapidly expanding application of the light modifying properties of glass structures involves the drawing of fine filaments of highly purified glass, more commonly referred to as optical fibers, that direct light signals between light transmitting and receiving locations. The use of optical fiber communication networks has grown to provide an alternative to coaxial cable systems. Advantages provided by optical fiber communications networks include lower cost, the use of fewer signal repeaters for correcting signal distortion, and a higher signal carrying capacity than coaxial cable networks.
Interconnection of fiber optic networks requires high precision devices in the form of optical connectors that join optical fibers to peripheral equipment and other optical fibers while maintaining adequate signal strength. In operation an optical connector centers the small fiber so that the light gathering core lies directly over and in alignment with a light transmitting source or another fiber. Following correct positioning of an optical fiber, known connecting structures such as crimped connections, soldered connections, spliced connections and the like may be used to maintain alignment between sections of optical fiber.
Soldered connections, in the form of optical fiber splices, terminations and hermetic seals, may include a thin metallic layer over the surface of an optical fiber adjacent to the position at which the splice, termination or seal will be made. Metal coating of terminal ends of optical fibers facilitates solder bonding and attachment of one optical fiber to another optical fiber, to a laser diode, to a ferrule and to connection points of optoelectronic devices.
U.S. Pat. No. 4,033,668 describes a method for joining a first glass member, such as an optical fiber, to a second member by means of solderable splices and terminations, which additionally can form hermetic seals. The splice, termination or seal may be formed after coating the peripheral surface of the glass member with a thin adhering metallic layer. After properly positioning the coated glass member, formation of a splice termination or seal with a corresponding member, may use heated solder to flow around the joint to form a bond between the members when cooled. When the second member is also formed of glass, a thin adhering metallic layer, similarly formed on the peripheral surface thereof, provides a solder receptive surface in the area of the intended joint. Metal may be applied to terminal portions of e.g. optical fibers by dipping them into a paste containing conductive metal particles.
U.S. Pat. No. 5,100,507 addresses finishing techniques for lensed optical fibers. The process of finishing an optical fiber places an integral lens and a metallized outer coating on the end of an optical fiber. Metal may be deposited on the ends of optical fibers using known sputtering techniques. Materials deposited in this way include titanium, platinum and gold. Application of metal close to the lensed end of an optical fiber allows the formation of a soldered connection very close to the tip of the fiber. This limits subsequent movement of a lensed fiber relative to an aligned optical device.
Prior description of soldered connections involves individual processing of metallized ends of optical fibers. Optical fiber handling represents a challenge for the optical fiber industry. Manufacturing operations may include a number of steps requiring handling of long and short lengths of optical fiber. These lengths of optical fiber are fragile filaments requiring careful handling and more efficient processes to accelerate the production of optical fibers for communication links and related devices. With a growing demand for optical fiber systems and devices, there is a need for processing a plurality of optical fibers simultaneously.
A filament organizer according to the present invention provides a suitable article for pre-positioning and holding a plurality of filaments, particularly optical fibers. Lengths of filaments, whether long or short, may be coiled inside suitably sized containers attached to a frame of the filament organizer. Pre-positioned filaments occupy a preferred and precise location and orientation allowing convenient treatment of terminal portions of filaments to apply materials over selected areas of the filaments. Suitable materials, such as metals and metal oxides, may be applied using, e.g. vapor deposition techniques. Metals may be applied to facilitate soldering and hermetic seal formation while the application of metal oxide and related materials may be used to apply e.g. a non-reflective coating over the surface of a filament.
A filament organizer according to the present invention further provides secure retention for an array of multiple optical fibers, precisely positioning their tips according to the requirements of designated process steps. This allows easier management of fiber tips, preventing them from making contact with each other during manufacturing processes. Use of a filament organizer allows consistent, reproducible placement of coatings and deposits, including inorganic coatings, organic coatings, antireflective coatings and combinations thereof, over a commonly prescribed area of each of a plurality of filament ends, such as the tips of optical fibers.
A preferred method of applying material, particularly oxide coatings, to the ends of filaments involves vapor deposition inside evacuated chambers. As an alternative, metal coatings may be applied to filaments using well known processes including electroless plating and electrolytic plating. Filament organizers according to the present invention may either include or be attached to a structure designed for use with suitable processing equipment. A filament organizer includes a filament clamp to hold the ends of filaments during coating, as by vacuum deposition of vaporized materials. The filament clamp may have process dependent, interchangeable parts depending upon the process in which it may be used.
More particularly a filament organizer comprises a filament container to hold a major portion of a filament. A filament clamp, having a spaced-apart relationship from the container, retains one or more filaments extending from the container. The filaments extend in a substantially parallel array over a frame between the container and the clamp. A frame has a first frame member parallel to a second frame member separated by the filament clamp.
The present invention also includes a filament positioning frame comprising a first gripping plate attached in opposing relationship to a second gripping plate. A filament clamp, is held in spaced-apart relationship to the first gripping plate and the second gripping plate using a frame that joins at least the first gripping plate to the filament clamp. The frame has a first frame member parallel to a second frame member.
Definitions
For clarification, the following definitions provide the meaning of terms that may be used throughout this specification.
The term xe2x80x9cfilamentxe2x80x9d refers thread-like structures preferably ceramic structures, particularly optical fibers.
Use of the terms xe2x80x9ccoatingxe2x80x9d or xe2x80x9cdepositxe2x80x9d herein refers to application of selected materials, including metals and metal oxides, to filament surfaces using any of a variety of methods of application, preferably vacuum coating or deposition. Coatings and deposits include known materials that provide antireflective coatings.
A xe2x80x9cfilament containerxe2x80x9d may include one or more xe2x80x9cfilament holdersxe2x80x9d in the form of substantially planar envelopes or pouches each holding a single filament. A stack of holders satisfies the definition of a container according to the present invention.
The beneficial effects described above apply generally to the exemplary devices and mechanisms disclosed herein of a filament organizer and a filament positioning frame. The specific structures through which these benefits are delivered will be described in detail hereinbelow.